diff options
Diffstat (limited to 'hash.c')
| -rw-r--r-- | hash.c | 54 |
1 files changed, 35 insertions, 19 deletions
@@ -1,4 +1,4 @@ -/* $Id: hash.c,v 1.12 2004/01/30 20:57:56 reinelt Exp $ +/* $Id: hash.c,v 1.13 2004/02/27 06:07:55 reinelt Exp $ * * hashes (associative arrays) * @@ -23,6 +23,9 @@ * * * $Log: hash.c,v $ + * Revision 1.13 2004/02/27 06:07:55 reinelt + * hash improvements from Martin + * * Revision 1.12 2004/01/30 20:57:56 reinelt * HD44780 patch from Martin Hejl * dmalloc integrated @@ -181,9 +184,10 @@ static HASH_ITEM* hash_set_string (HASH *Hash, char *key, char *val) Item=&(Hash->Items[Hash->nItems-1]); - Item->key = strdup(key); - Item->val = strdup(val); - Item->Slot = NULL; + Item->key = strdup(key); + Item->val = strdup(val); + Item->root = 0; + Item->Slot = NULL; hash_got_string: // set timestamps @@ -213,16 +217,23 @@ void hash_set_delta (HASH *Hash, char *key, char *val) // allocate delta table if (Item->Slot==NULL) { + Item->root = 0; Item->Slot = malloc(DELTA_SLOTS*sizeof(HASH_SLOT)); memset(Item->Slot, 0, DELTA_SLOTS*sizeof(HASH_SLOT)); } // shift delta table - memmove (Item->Slot+1, Item->Slot, (DELTA_SLOTS-1)*sizeof(HASH_SLOT)); + // <--- don't move 63 bytes just to insert one byte - this is _very_ + // slow on my Elan SC520 or GEODE SC1100 + //memmove (Item->Slot+1, Item->Slot, (DELTA_SLOTS-1)*sizeof(HASH_SLOT)); + + // move the pointer to the next free slot (wrapping around if necessary + if (--Item->root < 0) Item->root = DELTA_SLOTS-1; // set first entry - gettimeofday(&(Item->Slot[0].time), NULL); - Item->Slot[0].val=number; + gettimeofday(&(Item->Slot[Item->root].time), NULL); + Item->Slot[Item->root].val=number; + } @@ -270,6 +281,7 @@ double hash_get_delta (HASH *Hash, char *key, int delay) timeval now, end; int i; double dv, dt; + HASH_SLOT *pSlot; // lookup item Item=hash_lookup(Hash, key, 1); @@ -277,33 +289,38 @@ double hash_get_delta (HASH *Hash, char *key, int delay) if (Item->Slot==NULL) return 0.0; // if delay is zero, return absolute value - if (delay==0) return Item->Slot[0].val; + if (delay==0) return Item->Slot[Item->root].val; // prepare timing values - now=Item->Slot[0].time; + now=Item->Slot[Item->root].time; end.tv_sec = now.tv_sec; end.tv_usec = now.tv_usec-1000*delay; if (end.tv_usec<0) { end.tv_sec--; end.tv_usec += 1000000; } - + // search delta slot - for (i=1; i<DELTA_SLOTS; i++) { - if (Item->Slot[i].time.tv_sec==0) break; - if (timercmp(&Item->Slot[i].time, &end, <)) break; - dt = (now.tv_sec - Item->Slot[i].time.tv_sec) + (now.tv_usec - Item->Slot[i].time.tv_usec)/1000000.0; + for (i=1; i<DELTA_SLOTS; i++) { + pSlot = &(Item->Slot[(Item->root+i) % DELTA_SLOTS]); + if (pSlot->time.tv_sec==0) break; + if (timercmp(&(pSlot->time), &end, <)) break; + dt = (now.tv_sec - pSlot->time.tv_sec) + (now.tv_usec - pSlot->time.tv_usec)/1000000.0; } - + + // empty slot => use the one before - if (Item->Slot[i].time.tv_sec==0) i--; + if (pSlot->time.tv_sec==0) { + i--; + pSlot = &(Item->Slot[(Item->root+i) % DELTA_SLOTS]); + } // not enough slots available... if (i==0) return 0.0; // delta value, delta time - dv = Item->Slot[0].val - Item->Slot[i].val; - dt = (now.tv_sec - Item->Slot[i].time.tv_sec) + (now.tv_usec - Item->Slot[i].time.tv_usec)/1000000.0; + dv = Item->Slot[Item->root].val - pSlot->val; + dt = (now.tv_sec - pSlot->time.tv_sec) + (now.tv_usec - pSlot->time.tv_usec)/1000000.0; if (dt > 0.0 && dv >= 0.0) return dv/dt; return 0.0; @@ -360,4 +377,3 @@ void hash_destroy (HASH *Hash) Hash->sorted=0; Hash->Items=NULL; } - |